In a conventional manufacturing line of an absorbent article such as a disposable diaper, the absorbent article is manufactured, for example, by superposing and processing a plurality of continuous sheets.
In this manufacturing line, the continuous sheet is reeled out from a whole cloth roll and continuously transported in the transporting direction. At the time of this transport, there is a risk that the continuous sheet will meander. Therefore, a meandering correction apparatuses is arranged at each of the appropriate positions of the transport path. With these apparatuses, for example, the position of the continuous sheet in the width direction is corrected so that the central position of the continuous sheet in the width direction corresponds with the central position of the manufacturing line in the width direction of the line.
The meandering correction apparatus includes a roll around which the continuous sheet is disposed, for example. Then, based on a detection signal from an edge sensor that detects a position of an edge of the continuous sheet in the width direction, the meandering of the continuous sheet in the width direction is corrected by oscillating the roll.
The edge sensor includes a sensor head that has a detecting section such as a phototube, and this sensor head is stopped at a predetermined stop position in the width direction. In the stopped state, the sensor head detects a change in the light shielding condition that changes along with the shifting of the edge position of the continuous sheet in the width direction which is detected based on the changes in the amount of received light by the detecting section. In this manner, the position of the edge of the continuous sheet is detected (Patent Literature 1).